Balanced slide-valve



(No Model.)

H. MOON.

BALANCED SLIDE VALVE No. 450,470. Patented Apr. 14, 1891.

vwowtoz lead out of the valve-chest at its lower side,

UNITED STATES PATENT OFFICE.

HERMON MOON, OF GROVE CITY, PENNSYLVANIA.

BALANCED SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 450,470, dated April 14, 1891. Application filed December 15, 1890. Serial No.3'74 819. (No model.)

To all whom it may concern.-

Be it known that I, HERMON MOON, a citizen of the United States, residing at Grove City, in the county of Mercer and State of Pennsylvania, have invented certain new and useful Improvements in Balanced Slide-Valves, of which the following is a specification, reference being had therein to the accompanying drawings, in which Figure 1 represents a horizontal sectional view taken on the line 02'- a: of Fig. 3; Fig.2, a vertical sectional view taken on the lines as wof Figs. 1 and 3; Fig. 3, a vertical transverse section on the line 00" 0c" of Fig. 1, and Fig. 4 a detail side elevation of the parts of the valve.

The invention relates to certain improvements in balanced slide-valves for reciprocating steam-engines; and it has for its objects essentially to provide for readily starting the engine at a full head of steam and also to take up the wear of the contiguous surfaces of the valve and valve-seat, as will more fully hereinafter appear.

Referring to the annexed drawings, a indicates an ordinary steam-cylinder, which has formed integral with it at one side a horizontal cylindrical valve-chest I), provided with the usual heads and stuffing-boxes and communicating with the respective ends of the cylinder by means of the steam-ports a a. The valve-chest is shown as formed integral with the cylinder; but it is evident that it may be formed separate and bolted thereto, if desired. It is also evident that the valvechest may be formed or located on either side of the cylinder or on top of the same, instead of on the left-hand side of the cylinder, as shown. The live-steam pipe (2 connects witha steam-passage f, which latter leads into the side of the valve-chest about midway its length. The two exhaust-ports g g preferably one port being near each end. A casing g is bolted over the exhaust-ports, so as to connect both of them with the exhaust-pipe e. The valve 0 snugly fits the interior of the valvechest and is connected to the usual valve-rod cl. Longitudinal grooves c c are formed in the exterior of the valve from end to end to permit the exhaust-steam to pass freely and continuously around the valve and out at the exhaust-port, no matter in what position the valve may be. horizontal transverse cylindrical recess h, out of the bottom of which leads a transverse slot h, which is preferably similar in shape and length to the engine-ports a a, and with which it alternately registers and communicates when in operation. A tube d is connected to the forward end of the valve and communicates with a recess h in the same, this tube extending out through a stufling-box in the forward end of the valve-chest a suitable distance and being provided at its end with a chamber at, which is provided with a petcock d', whereby the condensed steam collected in the valve may be blown off. A section it of the valve is made movable and provided with a piston-like extension, which is adapted to Work truly within the cylindrical recess in the valve and which may be provided with a suitable annular packing to render it steam-tight. The outer surface of this movable section h is curved to conform to the interior of the valve-chest and to the general contour of the valve. This section may be provided with shoulders 0 near its ends, which abut against similar shoulders formed on the valve, and thereby serve to assist in guiding the section in its movements. The section is kept pressed normally outward against the interior of the valve-chest by a coil-spring interposed between its lower end and the bottom of the recess h, whereby all Wear of the contiguous parts of the valve and chest may be readily and automatically compensated for and taken up. A longitudinal groove j is formed in the exterior of the movable section and is of sufficient length to communicate with the steam-inlet throughout the full length of the stroke of the valve, and a steam-passaget'connects this groove with the interior of the valve, whereby the valve will always remain full of live steam.

The operation will be apparent from, the foregoing, and is briefly as follows: When the steam is admitted, it immediately fills the interior of the valve and remains therein ready for immediate access to the cylinder, the pressure of the steam upon the inner end of the movable section serving to assist the spring in keeping the section pressed against the valve-chest. \Vhen the valve is moved so that The valve is formed with a chestand provided with an interior cylindrical chamber, a steam-port leading out of this chamber and adapted to connect alternately with the steam-ports of the engine, a movable section carried by the valve and adapted to normally press against the interior of the valve-chest and provided with a piston-like extension working in the said cylindrical chamber of the valve, a spring under the said movable section to keep it normally pressed against the interior of the valve-chest, and steam-passages formed through the said movable section, as and for the purposes described.

2. The combination of a cylindrical valvechest provided with inlet and exhaust ports and ports leading to the cylinder, a cylindrical reciprocating valve provided with steampassages through it connecting the inlet to the cylinder-ports, and a tube connected to the interior of the valve and extended out of the valve-chest and provided with a cock, as and for the purposes described.

3. The combination of a valve-chest provided with steam inlet and exhaust ports and ports leading to the cylinder, and a chambered valve adapted to reciprocate therein, this valve being provided with a longitudinal exterior groove serving to continuously connect the exhaust-ports, as and for the purposes described.

In testimony whereofl affix my signature in presence of two witnesses.

IIERMON MOON.

Witnesses:

J AMES SIMPSON, RICHARD WILsoN. 

